Position on Hydrogen

Hydrogen is currently hyped as the solution for everything. Though while it is very important for the decarbonisation of certain processes (iron, cement, chemical industry) there is not much else where it makes any sense unless it is needed chemically.
Especially it makes absolutely no sense to transport hydrogen over any longer distance or build an infrastructure for anything but (really) green hydrogen.
Because of the energetic inefficiency of hydrogen and the high climate impact of leaking hydrogen the use should be focused on those applications where it is really needed.
Using it as an energy carrier for land transport makes no sense and projects where it is generated overseas also make no sense. For long distances the transport will use more energy than what is contained in the hydrogen being transported.
Building infrastructure for blue hydrogen (or any other fancy color…) also makes no sense. If there is no structure in place right now it does not make any sense to build one that needs to be replaced in the short term.

I think we should take a clear position on this. It seems like all other parties dream of alternative physics and some magical technology that makes it possible to overcome limitations like gas dynamics.

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Hello there, can you please add sources to your statements (inefficiency, impact of leaking, examples where it made no sense etc.) …?

Greenhouse gas impact of hydrogen:

(Actual study is linked in the article)

Montpellier is cancelling hydrogen buses due to high cost compared to battery electric buses:

As for the efficiency my statement is based on knowing the physics behind the processes. I would have to dig for sources. There is a lot of misleading information about the efficiency of electrolysis as some take the theoretical limit and then state how many percent of that they reach.

Communication about advances in hydrogen is quite often biased and hyped, i.e. there recently was a report that vibrating the electrodes can increase the output by a factor of 14. Though not in relation to the energy input but in relation to a certain design of electrodes that achieved a higher throughput and not higher efficiency (i.e. more hydrogen for a proportionally higher amount of energy, but the system got smaller).

Typically you can assume electrolysis to work with up to about 70% efficiency, fuel cells are in the same ballpark. So you are down to about 50% efficient with generating hydrogen and turning it back into electricity, no storing included…

Compressing hydrogen to 700 bar (typical pressure in a car tank) needs about 10% of the energy contained in the hydrogen. Filling hydrogen from one tank to the next needs about that amount of energy again (a higher pressure has to be generated to make it move to the other tank).

A fuel cell vehicle needs about 2.5 to 3 times as much energy as a battery based vehicle. Plus it needs a lot of space for the tanks (25 liter per kilogram at 700 bar), has a maintenance intensive high pressure system and quite a bit of platinum and palladium in the fuel cells (experimental cells without precious metals do not nearly reach the efficiency and life time).

And those are physical limitations, no technology can solve this.


When talking about hydrogene, we could also include efuels in this discussion, as the arguments for or against it seem to be quite similar in questions of efficiency.

I want to inform you, that PPLU has a draft bill on a subject directly related to efuels, which you can find here: https://piraten.lu/fr/faire-du-luxembourg-un-precurseur-dans-le-captage-de-co2/ (in French only for the moment)
It is about the development of carbon capture and stockage activities, which are necessary following an IPCC report from 2018. Maybe we could open a separate thread for this, if you think that that would better be discussed in a separate category.


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Hi Gilles,

I think we can keep these two topics together as (green) hydrogen is a prerequisite for eFuels.

Since eFuels release the CO2 again when burned they can not contribute to lowering the CO2 level in the atmosphere. At best they do not contribute to a higher CO2 levels. Though they also cause nitric oxide.

There currently are several industrial processes (i.e. ammonia synthesis) that use hydrogen generated from fossil fuel resources, which causes a lot of CO2 emissions. Also there are industrial processes that need to be decarbonized and will require hydrogen in the future (steel, cement…). At the moment we do have but minimal production capacities for green hydrogen. Building them will require a major effort in adding renewables and the electrolyzer capacity.

So aside from applications for which we currently have no other solution (long haul flight and shipping) I do not see eFuels as any option at all (besides running classic cars, but this is a rather small niche). There simply is no way we can build sufficient capacities for producing them in time. And by in time I refer to climate change as well as to the phase out of internal combustion engines due to economic reasons.

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